﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace _10.Accurasy0._00001
{
    class Program
    {
        static void Main()
        {
            double sum = 0;
            double precision = 0.0001;

            double previous = 1;

            for (int i = 2; ; i++)
            {
                double current = Math.Pow(-1, i) * (1.0 / i);
                sum += current;

                if ((Math.Abs(previous) - Math.Abs(current)) < precision)
                {
                    break;
                }

                previous = current;
            }
            Console.WriteLine(sum);

        }

    }
}



